Remove the door panel and lubricate the parts in side the door.
I used WD-40. Works fine now after lubricating. I had the
similar problem with my driver side door on my 2003 ZX3. Key
would not unlock door, outside door handle would not open door.
Inside door handle would open door but it needed a little extra
force to open. Inside lock worked fine.

You will have to remove the remote mirror housing cover before
you can take the door panel off. Remove the plastic nut on the
remote mirror control, the cover is held on with three snap
fasteners. Also there are two hidden screws. One is under the
small cap behind the handle used to open the door, the other
is behind the cap on the face of the handle used to close the
door. You will likely need a torque screwdriver to remove some
of the screws. As I recall the hidden screws and some of the
others require a 1/4 inch socket.

I am going to assume you have power windows. My 2003 ZX3
doesn't, so I have no idea how the power windows controls are
attached to the door and or door panel.

After you get the door panel off you will have to peal off
the insulation panel. I used a knife to cut the adhesive. The
adhesive will restick when you put the insulation panel back
in place after lubricating.

Took me about 30 minutes and little sweat to do this job.